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LO input for AD8333

Question asked by Heta on Jan 6, 2016
Latest reply on Jan 8, 2016 by Heta



How important/mandatory it is to use LVDS driver for LO input pins of AD8333? Is there any other alternative IC or circuit that I can use instead of it? I tried using LNA with the ac coupling circuit as shown in the datasheet, but I feel that it doesn't give the correct output. I get same amplitudes for I and Q irrespective of the input I give, so basically it always shows 45 degrees of phase between the real and the imaginary value. As far as I understood the working of AD8333, I suppose both of the amplitudes should vary so that I can deduct the exact phase angle between them. Do guide me if my concept about the IC is wrong. Is AD8333 supposed to give same amplitude levels for I and Q? If so, how do I calculate the phase and amplitude of my input based on output waveforms?


The main problem is that no IC manufacturers have made spice models available for LVDS. There are IBIS models which I tried to convert into spice models via many softwares, but the spice model it generates is too complicated to be able to import or create a model in Multisim or Orcad/Pspice as it generates many .subckt files. Kindly suggest me if there is any other way to provide LO signals apart from LVDS driver. Thanking you.


Best regards,